A leader of a hardline Egyptian Islamist group that fought the state in the 1990s warned that the army had driven the nation to the "edge of a precipice" since he fled the country after president Mohamed Morsi's ouster in July.
The state and Islamists are old foes in Egypt, a strategic US ally which has a peace treaty with Israel and controls the Suez Canal.
Egypt has been torn by the worst internal strife in its modern history since the army deposed the Islamist Morsi amid mass protests against his rule.
Assem Abdel-Maged of the Al-Gamaa Al-Islamiya told the Qatar-based Al Jazeera network he expected the situation in Egypt to deteriorate, saying protests "will be what breaks this coup."
He said the military made a "major mistake" by siding with "religious, political, and social minorities," an allusion to Christians and secular-minded Egyptians.
"Everything that happens in Egypt now is in the interests of the minorities. Therefore the situation cannot continue this way, and the army must review its position quickly because the country is on the edge of a precipice," Abdel-Maged said.
Abdel-Maged, who once shared a prison cell with Al-Qaeda leader Ayman Al-Zawahri, was jailed for 25 years until 2006 for a role in the 1981 assassination of president Anwar Sadat. He now faces charges of inciting the killing of protesters.
Egyptian security officials said Abdel-Maged fled to Qatar via the sea or the border with Libya. Qatar is one of the few Arab states that were sympathetic to Islamists during Morsi's year in power, supplying Egypt with billions of dollars in aid.
Al-Gamaa Al-Islamiya renounced violence more than a decade ago and entered mainstream politics after president Hosni Mubarak's downfall in 2011. It became a close ally of Morsi's Muslim Brotherhood during his one year in office.
"If the army leadership do not wake up and realise what is happening, then, unfortunately, matters will become worse in Egypt," Abdel-Maged said in the interview with Al Jazeera late on Saturday. "They will find that in the end they'll have only the tanks and soldiers on their side in a confrontation with the entire Umma (Islamic nation)."
The army deposed Morsi after mass protests against his rule. Since then hundreds of his supporters have been killed in a security crackdown while bomb attacks and shootings targeting the security forces have become commonplace, killing around 200 soldiers and policemen, most of them in the Sinai Peninsula.
The state has declared a war on Islamist militants.
In his last weeks in office, Morsi appointed a Al-Gamaa Al-Islamiya member as governor of Luxor, a city on the Nile south of Cairo where members of the group killed 58 tourists in 1997.
*This story has been edited by Ahram Online